// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_BASE_VIDEO_RENDERER_H_
#define MEDIA_BASE_VIDEO_RENDERER_H_

#include "base/callback_forward.h"
#include "base/macros.h"
#include "media/base/media_export.h"
#include "media/base/pipeline_status.h"
#include "media/base/time_source.h"

namespace media {

class CdmContext;
class DemuxerStream;
class RendererClient;

class MEDIA_EXPORT VideoRenderer {
public:
    VideoRenderer();

    // Stops all operations and fires all pending callbacks.
    virtual ~VideoRenderer();

    // Initializes a VideoRenderer with |stream|, executing |init_cb| upon
    // completion. If initialization fails, only |init_cb|
    // (not RendererClient::OnError) will be called.
    //
    // |cdm_context| can be used to handle encrypted streams. May be null if the
    // stream is not encrypted.
    //
    // |wall_clock_time_cb| is used to convert media timestamps into wallclock
    // timestamps.
    virtual void Initialize(DemuxerStream* stream,
        CdmContext* cdm_context,
        RendererClient* client,
        const TimeSource::WallClockTimeCB& wall_clock_time_cb,
        const PipelineStatusCB& init_cb)
        = 0;

    // Discards any video data and stops reading from |stream|, executing
    // |callback| when completed.
    //
    // Clients should expect |buffering_state_cb| to be called with
    // BUFFERING_HAVE_NOTHING while flushing is in progress.
    virtual void Flush(const base::Closure& callback) = 0;

    // Starts playback at |timestamp| by reading from |stream| and decoding and
    // rendering video.
    //
    // Only valid to call after a successful Initialize() or Flush().
    virtual void StartPlayingFrom(base::TimeDelta timestamp) = 0;

    // Called when time starts or stops moving. Time progresses when a base time
    // has been set and the playback rate is > 0. If either condition changes,
    // time stops progressing.
    virtual void OnTimeProgressing() = 0;
    virtual void OnTimeStopped() = 0;

private:
    DISALLOW_COPY_AND_ASSIGN(VideoRenderer);
};

} // namespace media

#endif // MEDIA_BASE_VIDEO_RENDERER_H_
